I purchased a 2018 Giant Quick e+ for commuting. Giant uses a modified yamaha PW-X system they have branded "syncdrive pro". The bike is great but the headlight it comes with stinks. I would like to drive a light with more lumens off the battery. The yamaha system uses a 36V battery that it drops down to 6V for the headlight (and presumably the tail-light).
For the 6V systems there are some options including lights from lupine SL S Yamaha E-Bike Light (500 lumen) and supernova mini2 (235 lumen). I am getting one of of lupine lights to see if 500 Lumen is enough.
The question: I am not sure why Yamaha decided to use 6V internally, except for perhaps cost. You can buy a 36V DC to 12V DC converter that is waterproof. IF installed the converter (and find a place for it) it seems reasonable that I could rewire the bike to use a 12V light. This would let me have a light that drives up to 1100 lumens. Am I completely nuts or is this reasonable?